Audion circuit battery control



' July '7, 1931'.

F. J. woLFF 1,813,334

AUDIoN cumul; BATTERX CONTROL Filed Jne '26,' 192e Frmmyna. wow

I Patented July-"17, 1.931

UNITED STATES PATENT oFFIcE FRANKLYN J'. WOLFF, 0F TBENTQN, NEW JERSEY.

AUDION' CIRCUIT BATTERY CONTROL Application med June I26,1926. Serial No. 118,767,

4 Figure 1 1s a diagrammatic view oir'l an 15 audion circuit including one stage of ampli# fication and the plate and filament batteries, the position of the control switch constituting the invention being shown.

Figure 2 is a topf plan view of the control:

' 20 switch.

While the invention is obviously applicable to any sort of an audion circuit comprising. plate and filament batteries, it i's`illustrated-1f` h as used in connection with the simple audioA clrcuit diagrammatically indicated at.10,th f plate and filament leads of which azrebroufgh tothe terminal block 11 for connectionffwi'thy.; the binding posts 12. The use of thejinVe/II: -the'filament battery circuit ahead of the plate tion involves no modification of the ordinary connection" of the batteries with the circuit other than that it necessitates bringingthe mmus terminals .of the plate batteryflg and; the filament battery 15 to the circuit closer switch also may engage. The clip 21, however, is of greater length than the clip 22 and accordingly in the closin switch engages the cli 21 1n advance of engaging the clip- 22. Slnce the clip 21` is confplate battery return on the negative leg and the outer forked clip 22 with which, the

operation, the

ing the filament circuit.

nected to the minus terminal of the filament battery, as indicated at 23, the circuit on the filament battery will be closed .ahead of closing the circuit onthe plate battery of which the minus terminal is connected with the clip 22, as indicated at 24. Therefore, if the switch 17 be mo-ved into engagement with Athe clip- 21 and permitted to remain in this position for a short period, say threeor four minutes,;the audion filaments will be energized with no potential present on the plates. Thus kthe coating of the filaments will vbe 'caused to fiow back to them from the plate orelsewhyere that it may have been deposited int-he tubes. The filaments having thus been permitted to burn a short whileto restore their coating, .a further movement of the switch into engagement with the clip 22 will result in closing the plate battery circuit.-

' Itis immaterial whether the positive or negative leg of the filament be used for the plate battery return for the effective use of ty e invention and the diagrammatic view ilstrated in Figure 1 shows by full line the dotted line on 'the positive leg. The inventiony may-be carried out by any form of switch that will provide for closing battery circuit but the knife form illustrated is probably the mostl simple.

' The incorporation of the invention in radio receiving sets, where the -best arrangement of tubes as detectors and amplifiers has been secured, will result in maintaining the tubes 1 in the best condition and will 4obviate the necessity for their removal from the sockets. for reactivation with its consequent experimentation to again find the best arrangement.

The invention having been described, what is claimed as new and useful is:

1.A In an audion circuit in which a switch is interposed in the common leg of the plate oav and filament circuits, the method of main- 95 taining the activated condition of the filaments which comprises operating the switch to first closethe `filament circuit, and after an appreciable time further operating the switch to lclose the plate circuit without open- 2. In combination with an audion circuit including plate and filament circuits and separate energizing means for said plate and filament circuits, a three pole control switch having a movable element to electricall connect or disconnect said poles, one of saidy Oles being connected in the common lego the plate and filament circuits and the other poles respectively connected one to each of the remalning terminals of said energizing means, said-movable element being actuable to .first close the filament circuit and thereafter to close the plate circuit without opening the filament circuit, said movable element being retainable in either of its two circuit closing positions.

In testimony whereof he aiiixes his signa- E ture. 

